基质金属蛋白酶9及其组织型抑制因子1在高血压大鼠血液及组织中的变化

Changes of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 in serum and tissues in hypertensive rats

目的探讨肾血管性高血压大鼠(RHR)血清、脑及血管组织中基质金属蛋白酶9(MMP-9)和组织型基质金属蛋白酶抑制因子1(TIMP-1)的表达以及血压与两者的关系。方法雄性SD大鼠80只随机分成RHR组(40只)和假手术组(40只)。RHR组采用双肾-双夹法制作高血压大鼠模型,鼠尾测压仪测定血压。根据Longa5评分法和病理学结果确定脑卒中;Western blot和免疫组化测定脑组织和血管中MMP-9和TIMP-1的表达,双抗体夹心ELISA检测血清MMP-9和TIMP-1水平。结果与假手术组比较,RHR组大鼠术后2、4、6、8、10、12周血压均明显升高[(157±9.0)比(128±7.0),(176±10.0)比(122±6.0),(194±8.0)比(117±6.5),(202±12.0)比(124±8.0),(218±15.0)比(126.±8.5),(224±20.0)比(129.±9.0)mm Hg,均P<0.05];术后12周,RHR大鼠血清MMP-9高于假手术组[(783.4±109.79)比(573.4±109.59)ng/m L,P<0.05];而RHR大鼠血清TIMP-1低于假手术组[(313.02±83.9)比(976.19±191.1)pg/m L,P<0.05]。同时,RHR大鼠脑组织和血管MMP-9的表达均明显高于假手术组(均P<0.05),而TIMP-1的表达则均明显低于假手术组(均P<0.05)。Pearson相关分析显示收缩压与血清、脑及血管组织中的MMP-9水平均呈正相关(r=0.557,r=0.774和r=0.661,均P<0.05),而与TIMP-1水平均呈负相关(r=-0.481,r=-0.535和r=-0.685,均P<0.01)。结论肾血管性高血压大鼠血清、脑和血管组织中MMP-9表达升高,而TIMP-1表达降低。两者在血液和组织中的变化趋势保持一致,血压的升高与血液和组织中MMP-9的升高和TIMP-1的降低相关。

Objective To investigate the expressions of metalloproteinase-9 （MMP-9） in serum, brain and aorta matrix and tissue inhibitor of metalloproteinase-1 （ TIMP-1 ） in renovascular hypertensive rats （ RHR）, and to evaluate the association between blood pressure and levels of matrix metalloproteinase-9 （MMP-9） and tissue inhibitor of metalloprotein- ase-1 （TIMP-1）. Methods Eighty healthy male SD rats were randomly divided into RHR group （ n = 40） and sham-opera- ted group （n =40）. Hypertension was induced by two-kidney, two-clip （2K-2C）clamps. Systolic blood pressure （SBP） was measured every 2 weeks during 12 weeks using a tail pressure meter. Stroke was confirmed by Longa＇ s five-point scale and pathological examination. The expressions of MMP- 9 and TIMP-1 in the brain and aorta tissues were detected by Western blot and immunohistochemistry. The levels of serum MMP-9 and TIMP-1 were measured by double-antibody sandwich enzyme-linked immunosorbent assay （ DAS-ELISA）. Results Compared with the sham-operated group, SBP stayed signif- icantly elevated in the RHR group at 2, 4, 6, 8, 10 and 12weeks after the operation [ （157 ±9.0） vs. （128 ±7.0）, （176±10.0） vs. （122±6.0）, （194 ±8.0）vs. （117 ±6.5）, （202 ± 12.0）vs. （124 ±8.0）, （218 ±15.0） vs. （126 ±8.5）,and （224±20.0）vs. （129±9.0） mm Hg, allP〈 0.05]. 12 weeks after the surgery, the level of ser- um MMP-9 in the RHR group was kept significantly higher than that in the sham-operated group [ （783.4 ± 109. 79）vs. （573.4 ± 109.59） ng/mL, P 〈 0.05 ], and the serum TIMP-1 level was lower in the RHR group than that in the sham-op- erated group[ （313.02 ±83.9） vs. （976. 19 ± 191.1） pg/mL, P 〈0. 05]. MMP-9 expressions were significantly higher in the brain and aorta in the RHR group than that in the sham-operated group （ both P 〈 0.05 ） , and TIMP-1 expressions were lower than that in the sham-operated group（ both P 〈 0.05）. The Pearson correlation analysis showed that MMP-9 lev- els in serum,brain and aorta were positively correlated with systolic blood pressure （ r = 0. 557,r = 0. 774 and r = 0. 661 ,all P 〈0.05） , and TIMP-1 levels were negatively correlated with systolic blood pressure（r = -0. 481 ,r = -0. 535 and r = - 0. 685 ,all P 〈0.01）. Conclusions Hypertension induces increased MMP-9 and decreased TIMP-I in serum, brain and aorta in renovascular hypertensive rats. There are consistent alterations of circulating and tissue MMP-9 and TIMP-1 levels in renovascular hypertensive rats. There is a relationship between increased blood pressure and high MMP-9 and low TIMP- 1 in serum and tissues.